Differential leakage indicator



Sept 21. 1948. H. B, KIRKLEY DIFFERENTIAL LEAKAGE INDICATOR Patented Sept. 21, 1948 if UNITED-NQ14srArs-s PATENT oFFicEy,

l 'l I f 'jf2,449,556

l Y DIFERETIL LEAKAGE INDICATOR Henryxllflirkley, Camden, N. J. applicatie-nerdy 25, 1946, serial No. 686,097

g j V3fClaims".

1 `(Granted undenthe act of March 3, 1883, as

. l amended April 30,

A tank, piping system, automotive engine cylini der or closed container can be `checked for leakage by means of an indicatorof lthisfinvention which consists of two closed cylinders eachdivided into two chambers by a central orifice plate. One cylinder can be usedalone or the two' cylinders can be used together depending upon thesize of the leak to be indicated. Compressedlfair, or other pressure fluid, is admitted to the first lpair of chambers by a common supply line. The air then passes through the one or two orice plates of the one or two cylinders to the second chamber or pair of chambers and then by a common flexible line to the container being tested for leakage. If the container being tested is `an automotive engine the connection can be made at the spark plug hole. Three valves control the air flow and one gage indicates the static pressurein the first pair of chambers and another gage, connected across the orifice plates, shows the differential -pressure between the two pairs of chambers. The differential pressure is related to the rate of leakage past the engine piston rings or valve seats so that the differential gage can be used to indicate the rate of leakage.

The pressure readings in pounds on the differential gage can be converted to size of leak or rate of leakage in cubic feet of air, or fluid, per minute owing through the orifice and out through the cylinder or other container under test for leaks. No leakage is indicated by zero on the differential gage. A pressure-reducing valve is located in the air-supply line so that the pressure in the rst pair of chambers can be held constant as indicated by the static-pressure gage connected therewith. The static-pressure gage and the pressure in the first pair of chambers are held to a constant reading during a test period by the pressure-reducing Valve.

The smaller the leakage to be measured by this leakage indicator the smaller must be the orifice in the diaphragm or plate between the first and second chambers. Any convenient number of interchangeable diaphragm plates with their orifices of different sizes can be used in the leakage indicator to obtain accurate readings, and these are further controlled by stopcocks,

The principal object of this'invention is to provide a leakage indicator that accurately indicates the size of a leak or indicates in pressure or volume the flow of air, or a uid, through any re- 2 l stricted passages connected to the container to be tested for leaks. y

Another object is to provide an air-flow measuring device using a differential-pressure gage to indicate the airflow through a selected sizeoriflce between adjacent pressure chambers, one being held under a constant pressure," the otherrheld under `the reduced pressure `resulting from the amount of leakage from the container under test.

Stillv another object is to produce a leakage indicator that is accurate,compact, rugged, .portable; simple to build, to maintain andoperate, and with which the amOuntbfAIeakage," within selected limits, canbe quickly and accuratelywdetermined. y l. w

Theseland other objects of the invention, and the various features and details of thefconstruction,` operation and use thereof, 'areihereinafter more fullyset forth and* describedawith reference 20 to the accompanying drawing-iniwhich `likenumbersrefer to likeparts and in whichzx.

Fig. lis a schematic drawing of interior mechanismof -the leakage indicator;` Fi`g42is an isometric view of the exterior of *the leakage indicator in a case.

In Fig. 1 numeral I designates'the constanthigh-pressure chambers of the air or fluid reservoir. Number 2 designates the low-pressure chambers of said reservoir. Between chambers I and 2 are diaphragms 3, each having an orifice 4 therein andprovlding a passage through which air or fluid flows from chamber I into chamber 2. Orice 4 can be of various calibrated sizes according to the volume of leakage to be measured by the indicator. Diaphragm 3 is clamped between fianges and 6 of chambers I and 2 respectively by bolts 1, nuts 8 and washers 9.

Air or uid supply tube II has a shutoff valve 2 and also a pressure-reducing valve I3, Chamber I has a tube I4 connecting to one side of differential-pressure gage I 5 and from the other side tube I6 leads from chamber 2 to dierentialpressure gage I5. Tube I'I connects static-pressure gage I8 to chamber I through tube I4. Tube I9 connects chamber 2 through shutoff valve 24 and tube 20, with flexible tube 22 and coupling 2|. Fitting 23 connects flexible tube 22 to container 25 which is to be tested for leakage. shutoff valve 24, normally closed, can be regulated to increase or decrease the volume of air flow when necessary. It allows air or a fluid to now through an additional orifice 4 which can be and usually is of larger area as required when large leakages are being measured.

In Fig. 2 numeral 26 refers to a case enclosing the parts as indicated schematically in Fig. 1. Screws 21 hold the case 26 in place and handle 28 supports case 26 through bale wire 29 which fastens to case 26 by nuts I8.

The present invention provides a novel device that is readily portable and usable Where compressed air is available for instantly indicating the volume of leakage from any closed container to which this device is connected. It is also of relatively simple and inexpensive construction and entirely eiilcient and reliable in use.

Although a particular embodiment of this invention has been illustrated and described herein, it is intended that this invention not be limited to such disclosure, and changes `and modifications can be made and incorporated Within the scope of the claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon or therefor.

'I claim:

1. Apparatus for indicating leaks in an object, said apparatus comprising a conduit adapted to be connected at one end to the object and at the other end to a source of fluid under pressure, an obstruction in said conduit for restricting ow of fluid through said conduit, said obstruction having therethrough an orifice of small size compared with the size of the conduit, a differentialpressure gage connected to the conduit on opposite sides of said obstruction, :and a static-pressure gage connected to the conduit on the side of said obstruction remote from the object.

2. Apparatus for indicating leaks, said apparatus comprising a, conduit adapted to be connected at one end to an object to be tested and at the other end to a source of fluid under pressure, an obstruction in said conduit for restricting flow of fluid through the conduit, said obstruction having therethrough a, rst orice or small size compared with the size of the conduit and a second orifice of `different size from the iirst orice, means for selectively shutting ofi iioW of fluid through the second orice independently oi ilow of iluid through the first orice, a diierential-pressure gage connected to the conduit on opposite sides of said obstruction, and a static-pressure gage connected to the conduit on the side of said obstruction remote from thel object.

3. Apparatus for indicating leaks, said apparatus comprising a rst conduit, an outlet tube connecting one end of the first conduit with an object to be tested, an inlet tube connecting the other end of the conduit to a source of fluid pressure, a. second conduit separate from the iirst conduit, the second conduit being connected at one end by a, rst connecting tube to the outlet tube and at the other end being connected by a second connecting tube to the inlet tube, a shutyoi valvein one of the connecting tubes, a iirst i obstruction in the first conduit for restricting flow of fluid through the rst conduit, the rst obstruction having therethrough a iirst orifice of small size compared with the size of the rst conduit, a. second obstruction in the second conduit for restricting flow of fluid through the second conduit, the second obstruction having therethrough a second orice of small size compared with the size of the second conduit, the i'irst orice and second orifice being of different sizes, ya diierential-pressure gage connected to the rst conduit on opposite sides of the first obstruction, and a static-pressure gage connected to the'irst conduit on the side of the irst obstruction remote from the object.

HENRY B. KIRKLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,844,843 Dezendorf Feb. 9, 1932 2,832,567 Gardner Oct. 26, 1943 2,348,985 Lewis May 16, 1944 

